Non-stalling gasoline fuel compositions



United States Patent NON-STALLING GASOLINE FUEL COMPOSITIONS Gardner E. Gaston, Tarentum, and Donald W. Howard,

Verona, Pa, assignors to Gulf Research & Development Company, Pittsburgh, Pa., a corporation of Delaware No Drawing. Application April 6, 1956 Serial No. 576,529

7 Claims. (Cl. 44--66) This invention relates to non-stalling gasoline fuel compositions that are adapted to improve the operation of internal combustion engines under cool, humid atmospheric conditions. More particularly, the invention relates to gasoline fuel compositions that contain a small amount, sufficient to reduce the tendencies of the composition to promote stalling in an internal combustion engine of the spark ignition, reciprocating type, of a substituted amide selected from the group consisting of N,N- dialkylol alkanamides, N,N-dialkylol alkenamides, and N,N-dialkylol allcadienamides, wherein the acyl groups contain 8 to 22 carbon atoms, and the alkylol groups contain 2 to 3 carbon atoms.

When an internal combustion engine is operated under cool, humid atmospheric conditions, using a gasoline fuel having a relatively low 50 percent ASTM distillation point, engine stalling is apt to be encountered at idling speeds during the warm-up period, especially where engine idling occurs following a period of light load operation. Engine stalling under such conditions has been attributed to the partial or complete blocking of the narrow air passage that exists between the carburetor throatand the carburetor throttle valve during engine idling, by ice particles and/or solid hydrocarbon hydrates that deposit upon and adhere to the metal surfaces of the carburetor parts. Such icing of carburetor parts occurs as a result of the condensation of moisture from the air drawn into the carburetor and as a result of the solidification of such condensed moisture. The aforesaid condensation and solidification of moisture are caused by the refrigerating effect of rapidly evaporating gasoline. Accordingly, excessive engine stalling due to carburetor icing occurs as a practical matter only in the instance of gasolines containing a large proportion of relatively highly volatile components. In practice, engine stalling due to carburetor icing has been found to occur, under cool, humid atmospheric conditions, in connection with gasolines having a 50 percent ASTM distillation point below about 235 F.

Excessive engine stalling is, of course, a source of annoyance owing to the resulting increased fuel consumption, battery Wear and inconvenience of frequent restarting. it is therefore important that the inherent engine stalling characteristics of gasoline fuels be reduced substantially, where the 50 percent ASTM distillation point of such gasoline fuels is sufficiently low to cause a problem in this respect.

We have found that the stalling characteristics of gasoline fuel compositions having a 50 percent ASTM distillation point below about 235 F. and that normally tend to promote engine stalling due to carburetor icing are markedly improved by the incorporation therein of a small amount of a member selected from the group consisting of N,N-dia1kylol alkanamides, N,N-dialkylol alkenamides, and N,N-dialkylol alkadienamides, the acyl groups of which contain 8 to 22 carbon atoms, and the alkylol groups of which contain 2 to 3 carbon atoms. In one embodiment of the invention the gasoline composition also contains about 0.25 to about 0.75 percent ICC by volume of the composition of a light lubricating oil having a viscosity at F. of about 50 to about 500 Saybolt Universal seconds.

The alkylol-substituted amide anti-stalling agents disclosed herein can be characterized as polar, surface-active materials. While the invention is not limited to any theory of operation, it might appear that the polarity of the disclosed agents tends to cause orientation of the latter upon the metal surfaces of the throttle valve and other critical carburetor parts contacted by the gasoline composition, thus forming a moisture-displacing, residual coating on said carburetor parts, which coating tends to prevent the adherence to said metal surfaces of accumulations of ice of magnitudes sufficient to block the narrow air passages that exist in carburetor throats at engine idling conditions. It is also considered that the alkylol-substituted amides may orient themselves about small individual water or ice particles, thus tending to prevent the formation of macrocrystals of ice of a size suflicient to block carburetor air passages at engine idling conditions. Although the effectiveness of the herein disclosed addition agents is believed to be attributable at least in part to the polar characteristics thereof, this general explanation is somewhat negatived by the fact that many oil-soluble polar agents have little or no effect upon engine stalling due to carburetor icing.

When the herein disclosed alkylol-substituted amide anti-stalling agents are utilized in gasoline compositions that contain a small amount of a light lubricating oil, it might appear that the alkylol-substituted amides, by virtue of their afiinity for the lubricating oil, tend to attract the oil to the same critical carburetor surfaces referred to above, while simultaneously increasing the spreading and metal wetting characteristics of the oil, thus promoting the formation of an adherent oil film on the metal surfaces of the carburetor parts. The oil film therefore would appear to function similarly as the alwhere R is an alkyl group, an alkenyl group, or an alkadienyl group containing 8 to 22 carbon atoms and R'OH is an alkylol group containing 2 to 3 carbon atoms. The compounds of the above formula wherein R is an alkyl group containing 8 to 18 carbon atoms and R'OH is an ethylol group are especially effective for the purposes of this invention. For example, excellent results have been obtained with mixed amides derived from. coconut oil fatty acids and cliethylol amine. Coconut oil fatty acids are the mixed fatty acids derived from coconut oil and comprise predominantly saturated fatty acids containing an even number of carbon atoms from 8 to 18. The main component of coconut oil fatty acid is lauric acid, or n-dodecanoic acid. Accordingly, the main component of the preferred anti-stalling additive disclosed above is N,N-diethylol lauramide. Examples of other alkylol-substituted amides, the use of which is included by this invention, are N,N-diethylol caprylamide, N,N- diethylol n-octadecanamide, N,N-diethylol behenamide, N,N-diethylol oleamide, N,N-diethylol linoleamide, and

3 the corresponding N,N-dipropylol amides, such as N,N- dipropylol caprylarnide, etc.

The alkylol-substituted amide anti-stalling agents described herein are useful when incorporated in gasoline compositions of the type disclosed in an amount sufiicient to reduce the engine stalling characteristics thereof. For example, a good improvement in the stalling characteristics of gasolines of the type disclosed will normally be obtained by the addition thereto of the herein disclosed alkylol-substituted amides in amounts of at least 0003 percent by weight of the composition, i. e, about 9 pounds per thousand barrels of gasoline. Preferably the alkylol-substituted amide anti-stalling agents disclosed herein will be employed in proportions of at least about 0.005 percent by weight of the composition, i. e., about pounds per thousand barrels of gasoline. Excellent results have been obtained by the addition of an alkylolsubstituted amide of the kind disclosed herein to gasoline compositions in proportions between 0.005 percent and 0.05 percent by weight of the composition, i. e., between about 15 and 150 pounds per thousand barrels of gasoline, and this constitutes the preferred concentration range for the purposes of this invention. In most instances the concentration of the herein disclosed antistalling agents need not exceed about 0.1 percent by weight of the composition, even in instances of gasolines having severe engine stalling tendencies.

It will be appreciated that the optimum concentration of the disclosed alkylol-substituted amide anti-stalling agents can vary within the disclosed range according to the particular gasoline employed, since the problem of engine stalling due to carburetor icing is a function of the 50 percent ASTM distillation point of the gasoline. Thus, greater concentrations of the additive are normally desirable with decreasing 50 percent ASTM distillation point. The optimum concentration of the alkylol-substituted amide anti-stalling agents can also vary somewhat according to the particular make and model of engine in which the gasoline is used and also according to the severity of the atmospheric conditions encountered. With regard to the last mentioned factor, the problem of engine stalling due to carburetor icing resulting from the refrigeration by evaporating gasoline of moisture condensed from the atmosphere has been observed to be significant at temperatures between about and 50 F., e. g., F., and when the relative humidity is in excess of about percent, e. g., 75, 85, 99 percent. The optimum concentration of the alkylol-substituted amide antistalling agents will be one that is sufficient to effect a substantial reduction in the stalling tendencies of the fuel at the atmospheric conditions of temperature and humid ity which are likely to be encountered in service.

tactically speaking, the problem of engine stalling due to carburetor icing caused by rapid evaporation of gasoline occurs only in connection with gasolines having a 50 percent ASTM distillation point of not greater than about 235 F. While occasional engine stalling may occur as a result of carburetor icing at severe atmospheric conditions of temperature and humidity with gasolines having somewhat higher 50 percent ASTM distillation points, experience has indicated that the problem does not assume major importance except with gasolines of the character indicated. The problem of engine stalling due to carburetor icing is especially severe in connection with gasolines having a 50 percent ASTM distillation point of less than about 220 F. The invention is particularly useful in connection with such gasolines. The term gasoline is used herein in its conventional sense to include hydrocarbon mixtures having a percent ASTM distillation point of not more than about 392 F. and a 10 percent ASTM distillation point of not less than about 140.

As previously indicated, the gasoline compositions of this invention are additionally benefited with respect to non-stalling characteristics by the inclusion therein of a small amount of a lubricating oil having a viscosity at 100 F. of between about 50 and about 500 Saybolt Universal seconds; for example, an oil having a viscosity of about 100 S. U. S./ 100 F. can be used with advantage. Although highly paraflinic lubricating distillates can be used, lubricating distillates obtained from Coastal or naphthenic type crude petroleum oils are preferred because of their superior solvent properties. The lubricating oils utilized in the gasoline compositions of this invention can have been solvent-treated, acid-treated or otherwise refined prior to incorporation into the gasoline compositions of this invention. The lubricating distillates referred to are useful in the gasoline compositions of this invention in amounts of from about 0.25 to about 0.75 percent by volume of the composition, for example 0.5 volume percent. In such concentrations these lubricating distillates tend to assist the anti-stalling function of the alkylol-substituted amides and in addition function as upper cylinder and valve top lubricants. Greater amounts of the lubricating oil can be used but without appreciable further improvement in the stalling tendencies of the gasoline composition; however, the amount of lubnicating oil used should not be so great as to adversely affect the solubility and combustion characteristics of the ultimate gasoline compositions.

The alkylol-substituted amide anti-stalling agents of this invention can be incorporated into the base gasoline fuel compositions in any suitable manner. Thus, they can be added as such to gasoline or in the form of a dispersion or solution in solvents such as butanol, isopropanol, ethanol, methanol, 2-butoxy-ethanol, diethylene glycol monobutyl ether, benzene, toluene, heptane, kerosene, gasoline, mineral oil or the like, which solvents may or may not themselves additionally contribute to the antistalling characteristics of the ultimate composition. If desired, the disclosed alkylol-substituted amide anti-stalling agents can be incorporated in gasoline fuel compositions in admixture with other materials designed to improve one or more properties of the gasoline such as antioxidants, anti-gumming agents, anti-knock agents, e. g., tetraethyl lead, lead scavenging agents, e. g., ethylene dibromide, ignition control additives, de-icing agents, corrosion inhibitors, dyes and the like.

Gasoline compositions of this invention can be further illustrated by the following representative specific examples.

EXAMPLE I A gasoline composition according to this invention and having reduced engine stalling tendencies was prepared by incorporation in a sample of gasoline having a strong tendency as such to promote engine stalling of a commerical mixture of amido alcohols in the proportion of 25 pounds per thousand barrels of gasoline. The mixture employed comprised mixed amido alcohols derived from coconut oil fatty acids and diethanol amine, the chief.

component of the mixed amido alcohols being N,N-diethylol lauramide. Coconut oil fatty acids normally contain, on the average, approximately 8.6 percent cctanoic acid, 6.3 percent decanoic acid, 47 percent dodecanoic, or

7() Gravity, API 64.4

Anti-knock rating, Octane N0.:

Motor Method 79.3

Research Method 82.8

TEL, mL/gal 2.96

75 Vapor pressure, Reid, lb. 7.0

Distillation, gasoline:

EXAMPLE II An additional gasoline composition in accordance with this invention and having reduced engine stalling characteristics was prepared by admixture of Ultrapole DL in the proportion of 25 pounds per thousand barrels of gasoengine, the air supply to the carburetor of the engine being obtained by natural aspiration from a cold room atmosphere. The engine was equipped with. a standard Carter downdraft carburetor. The ambient temperature of the cold room was 40 F., and the relative humidity was 80 to 85 percent.

The first operating cycle of the engine included, after permitting the engine to cool to the ambient temperature of 40 F., starting the engine and running for 40 seconds at 2000 R. P. M. and then for seconds at 500 R. P. M. (idle) under no load, or until the engine stalls. Repetition of the foregoing cycle 20 times constituted one test.

Table Composition Concentra- Per 20 Operating Base Fuel 1,000 Bbls. Cycles Additive Base Gasoline,.206 F. 50% ASTM Distillation Point (Example I Base Fuel).

10 (avg, 8 tests).

2 Base Gasoline N,N-diethylo1 Lauramide 4.25 (avg.,4tests).

(Example I Additive). 3 Base Gasoline +0.5 Vol. Per- .do 25 3 (avg.,4tests).

cent 100 S. U. S./100 F. Texas Oil. 4 do 1 Engine tests showed no appreciable reduction in engine stalling due to carburetor icing compared with base gasoline, as such.

line, with the base gasoline described in Example I, to which there was also added 0.5 percent by volume of an approximately 100 S. U. S./ 100 F. Texas (Coastal) lubricating distillate, a sample of which had the following inspections:

The foregoing specific embodiments of the compositions of this invention are illustrative, and other suitable compositions Within the scope of this invention and having satisfactory anti-stalling characteristics can be prepared similarly by the substitution in the foregoing examples of other gasolines of the type disclosed herein and by the incorporation therein of the same or equivalent proportions Within the range disclosed of the alkylol'substituted amides disclosed herein. For example, good results can be obtained by incorporation in the gasoline of Example I of 0.01 weight percent of N,N-diethylol caprylamide, N,N-diethylol n-octadecanamide, N,N-diethylol behenamide, N,N,-diethylol oleamide, N,N-diethylol linoleamide, N,N-dipropylol caprylamide, N,N-dipropylol n-octadecanamide, and the like.

As heretofore indicated, the alkylol-substituted amide anti-stalling agents of this invention produce an appreciable improvement in the stalling characteristics of gasolines that normally promote engine stalling due to carburetor icing. To illustrate the nature of the improvement obtained, in the table following there are presented illustrative results obtained with engine tests using gasoline fuel compositions prepared in accordance with this invention. For purposes of comparison there are also presented in the table below the results obtained with engine tests carried out on a sample of the uninhibited test gasoline and on a sample of the test gasoline containing only 100 S. U. S./100 F. Texas oil.

According to the test procedure followed the fuel compositions to be tested were fed to a standard, 216 cubic inch displacement, 6-cylinder overhead valve Chevrolet From the results presented in the foregoing; table it will be seen that uninhibited gasolines having a 50 percent ASTM distillation point in the range disclosed possessed poor stalling characteristics. In tests of other uninhibited base fuels it was found that a gasoline having a 50 per cent ASTM distillation point of 230 F. produced an average (7 tests) of 1.4 stalls, whereas a gasoline having a 50 percent ASTM distillation point of 240 F. produced an average (19 tests) number of stalls approaching zero. From the data in the foregoing table it is also apparent that gasolines having a 50 percent ASTM distillation point within the range disclosed herein are markedly improved by incorporation therein of the herein disclosed proportions of the alkylol-substituted amide anti-stalling agents of this invention, either alone or in conjunction with the light lubricating distillates disclosed herein.

The alkylol-substituted amides disclosed herein have also been found to impart rust inhibiting characteristics to gasoline when used in the proportions disclosed herein. For example, gasoline containing Ultrapole DL in the proportion of 16 pounds per thousand barrels was subjected to a static rust test using distilled Water. After 52 days a steel specimen partly immersed in the test sample was found to have no rust on the portion exposed to the air phase, no rust on the portion exposed to the fuel phase, and no rust on the portion exposed to the water phase. In contrast, a steel specimen partly immersed in a sample of the uninhibited gasoline was found to have light rust on the portion exposed to the fuel phase after 42 days and heavy rust on the portion exposed to the water phase after 14 days.

To the gasoline fuel compositions of this invention there can also be added one or more additional additive agents designed to improve one or more characteristics of the gasoline fuel. For example, antioxidants, antiknock agents, ignition control agents, other de-icing agents, anti-rust agents, dyes, lead scavenging agents, anti-gumming agents and the like can be added to the compositions of this invention, and the invention specifically includes gasoline compositions containing such additives.

Numerous additional embodiments of the invention will readily suggest themselves to those skilled in the art. Accordingly, we do not intend to be limited by the foregoing description, but only by the terms of the claims appended hereto.

We claim:

1. A gasoline fuel composition comprising a major amount of a hydrocarbon mixture boiling in the gasoline range that has a 50 percent ASTM distillation point not greater than about 220 F. and that normally tends to promote stalling of internal combustion engines, and containing a small amount, sufficient to reduce the engine stalling characteristics of the gasoline composition, of a member selected from the group consisting of N,N-dialkylol alkanamides, N,N-dialkylol alkenamides, and N,N- dialkylol alkadienamides, whose acyl groups contain 8 to 22 carbon atoms, and Whose alkylol groups contain 2 t 3 carbon atoms.

2. The composition of claim 1 wherein the hydrocarbon mixture contains additionally about 0.25 to about 0.75 percent by volume of the composition of a light lubricating oil having a viscosity at 100 F of about 50 to about 500 Saybolt Universal seconds;

3. The composition of claim 1 wherein said small amount of said member is about 0.003 to about'0.1 percent by weight of the composition.

' 4. The composition of claim 1 wherein said small" amount of said member is about 0.005 to about 0.05 percent by weight of the composition.

5. A gasoline fuel composition comprisinga major. a.

amount of a hydrocarbon mixture boiling in the gasoline range that has a 50 percent ASTM distillation point not greater than about 220 F. and that normally tends to promote stalling of internal combustion engines, and containing a small amount, 'sutficient-to reduce the engine stalling characteristics of the gasoline composition, of N,N-diethylol lauramide.

6. A gasoline fuel composition comprising a major amount of a hydrocarbon mixture boiling in the gasoline range that has a percent ASTM distillation point not greater than about 220 F. and that normally tends to promote stalling of internal combustion engines, and containing, inthe proportion of about 25 pounds per thousand barrels of gasoline, mixed diethylol alkanamides, the acyl groups of which contain 8 to 18 carbon atoms.

7. A gasoline fuel composition comprising. a major amount of a hydrocarbon mixture boiling in the gasoline range that has a 50 percent ASTM distillation point not greater than about 220 F. and that normally tends to promote stalling of internal combustion engines, and containing (a) mixed diethylol alkanamides whose acyl groups contain 8 to 18 carbon atoms, and (b) a Coastal lubricating distillate having a viscosity at F. of about 100 Saybolt Universal seconds, said mixed diethylol alkanarnides being present in the proportion of about 25 pounds per thousand barrels of gasoline, and said Coastal lubricating distillate being present in the proportion of about 0.5 percent by volume of the composition.

References Cited in the file of this patent UNITED STATES PATENTS 2,089,212 Kritchevsky Aug. 10, 1937 2,668,522 Hickok et al. Feb. 9, 1954 2,706,677 Duncan et al. Apr. 19, 1955 OTHER REFERENCES Handbook of Material Trade Names, by Zimmerman et al., 1953 edition, Industrial Research Service, page 590.

Aviation Gasoline Manufacture, by Van Winkle, McGraw-Hill Book Co., 1944, pages 240 and 241.

UNITED STATES PAETENT OFFICE QEETHFEWHE @F CURRECTION Patent N00 2,843,464 July 15, 1958 Gardner En Gaston et alo It is hereby certified that error appears in the printed specification of the above number-ed patent requiring correction and that the said Letters Patent should read corrected below,

Column 3 line '71 for of not less" read me of not more Signed and sealed this 16th day of September 1955304 gSEAL) ttest:

KARL Ho .MINE ROBERT c. WATSON Attesting Officer Commissioner of Patents 

1. A GASOLINE FUEL COMPOSITION COMPRISING A MAJOR AMOUNT OF A HYDROCARBON MIXTURE BOILING IN THE GASOLINE RANGE THAT HAS A 50 PERCENT ASTM DISTILLATION POINT NOT GREATER THAN ABOUT 220*F. AND THAT NORMALLY TENDS TO PROMOTE STALLING OF INTERNAL COMBUSTION ENGINES, AND CONTAINING A SMALL AMOUNT, SUFFICIENT TO REDUCE THE ENGINE STALLING CHARACTERISTICS OF THE GASOLINE COMPOSITION, OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF N,N-DIALKYLOL ALKANAMIDES, N,N-DIALKYLOL ALKENAMIDES, AND N,NDIALKYLOL ALKADENAMIDES, WHOSE ACYL GROUPS CONTAIN 8 TO 22 CARBON ATOMS, AND WHOSE ALKYLOL GROUPS CONTAIN 2 TO 3 CARBON ATOMS. 